The present invention relates to an apparatus for making rubber component parts such as tire rubber component parts by winding an unvulcanized rubber tape, more particularly to a conveyor for the unvulcanized rubber tape.
In a pneumatic tire which is typical of rubber article, as shown in FIG. 11B, there are various rubber component parts (G) made of different rubber compounds, e.g. an inner liner rubber (Ga), sidewall rubber (Gb), chafer rubber (Gc), breaker cushion rubber (Gd), tread rubber (Ge), bead apex rubber (Gf) and the like.
Such rubber component parts (G) are conventionally made by means of an extruder or calender rollers in a form of rubber strip having the almost same width as the finished width or a wide rubber sheet cut into a rubber strip. Thus, the plant and equipment become inevitably large. On the other hand, as a tire is usually manufactured in various sizes, the total number of rubber component parts becomes very large, and accordingly it is necessary to prepare a large number of dies for the extruder. Further, it is necessary to change the facility when making a different type or size of tire. This takes much time. Therefore, in such a conventional method, it is difficult to establish a flexible manufacturing system which is capable of satisfying various marketing needs or demands, and it is also difficult to decrease investment in plant and machinery.
Recently, in a method of making a pneumatic tire, a method of making a rubber part was proposed, wherein a narrow rubber tape (P) is lap-wound into a final shape of the rubber part (G) as shown in FIG. 2 for example.
Therefore, an object of the present invention is to provide an apparatus for making rubber component parts, which is fit to use in such a lap-winding method and able to establish a flexible manufacturing system, while achieving downsizing of the plant and equipment and reductions in the investment in plant and machinery and the like.
According to one aspect of the present invention, an apparatus for making rubber component parts comprises:
at least one tape maker for making an unvulcanized rubber tape, each tape maker comprising an extruder for extruding unvulcanized rubber;
a winding drum around which the unvulcanized rubber tape is wound into a rubber component part;
at least one conveyor for conveying the unvulcanized rubber tape toward the winding drum, each conveyor comprising a conveyor belt winding around rollers and having a right side on which the unvulcanized rubber tape is put and a reverse side; and
at least one traverser for moving the conveyor belt in the axial direction of the winding drum.
Preferably, the right side of the conveyor belt is coated with a synthetic resin so that the unvulcanized rubber tape can be secured thereon by its self-bonding property during conveying, but does not stick thereto so as to be able to take it off therefrom when winding around the winding drum. Each conveyor preferably has an accumulator section in which the conveyor belt meanders for accumulating the unvulcanized rubber tape coming out from the tape maker, and the accumulator section having a variable capacity. Further, each conveyor has a swing section between the accumulator section and the traverser, in which the conveyor belt is twisted so that the widthwise direction of the conveyor belt is substantially at a right angle with respect to the traversing direction of the traverser.